Colliding Space Clutter

In the movie WALL-E, the Earth is surrounded by a dense field of orbiting junk. The problem of space debris is not that bad yet, but is potentially heading in that direction. A new report released by the National Research Council says the problem of space debris is getting worse and has passed a “tipping point.” The report says that while NASA has done a good job using their available resources to research the issue, decreased funding and increased responsibilities for the space agency is not a good combination for the future, and NASA has not been able to keep pace with increasing hazards posed by abandoned equipment, spent rocket bodies, and other debris orbiting the Earth.

“The current space environment is growing increasingly hazardous to spacecraft and astronauts,” said Donald Kessler, chair of the committee that wrote the report and retired head of NASA’s Orbital Debris Program Office. “NASA needs to determine the best path forward for tackling the multifaceted problems caused by meteoroids and orbital debris that put human and robotic space operations at risk.”

There’s enough debris currently in orbit to continually collide and create even more debris, raising the risk of spacecraft failures, the report notes. In addition, collisions with debris have disabled and even destroyed satellites in the past, as in the collision in 2009 between an Iridium satellite and a inoperative Russian satellite. Several recent near-misses of the International Space Station requiring evasive maneuvers and sending astronauts to the Soyuz vehicles as a precaution underscores the value in monitoring and tracking orbital debris as precisely as possible.

Debris objects in low-Earth orbit. This is an artist’s impression based on actual density data, and the objects are shown at an exaggerated size to make them visible at the scale shown. Image credit: ESA

It is fitting that Kessler lead this committee: he laid out a scenario back in 1978 called the Kessler Syndrome where the amount and size of objects in Earth’s orbit could eventually become so large that they would continually collide with one another and create even more debris, eventually causing a “cascade” of collisions which could make low Earth orbit unusable for decades.

From the new report, it appears the Kessler Syndrome is not just an abstract event that might occur in the future. It’s happening now. The amount of debris is now growing exponentially, as just two collisions since January 2007 has doubled the total number of debris fragments in Earth’s orbit, according to the NRC report.

NASA had asked for the report; specifically, NASA’s chief of safety and mission assurance, Bryan O’Connor, asked the NRC in 2010 to independently examine the agency’s work on debris.

“We thank the National Research Council for their thorough review in this report,” said NASA spokeswoman Beth Dickey. “We will study their findings and recommendations carefully and use them to advise our future actions in this important area of work.”

The report, however, does not provide NASA with many specific ideas but says NASA should develop a formal strategic plan to better allocate its limited resources devoted to the management of orbital debris. In addition, removal of debris from the space environment or other actions to mitigate risks may be necessary.

For example, NASA should initiate a new effort to record, analyze, report, and share data on spacecraft anomalies. This will provide additional knowledge about the risk from debris particulates too small to be cataloged under the current system yet large enough to potentially cause damage.

The report also suggests more work internationally on this problem, since it is a global problem caused by other nations besides the US. Over the past decade and a half, the world’s major space agencies have been developing a set of orbital debris mitigation guidelines aimed at stemming the creation of new space debris and lessening the impact of existing debris on satellites and human spaceflight. Most agencies are in the process of implementing or have already implemented these voluntary measures which include on-board passive measures to eliminate latent sources of energy related to batteries, fuel tanks, propulsion systems and pyrotechnics.

But the growing number of developing countries that are launching using satellites, and they need to be encouraged to use these measures as well.

In addition, NASA should lead public discussion of orbital debris and emphasize that it is a long-term concern for society that must continue to be addressed.

Congress also needs to be aware of the problem and provide adequate funding for the issue.